 
 (defmethod windowing-builder :sliding
   [window] 
+  (when (ordered-log? window)
+    (throw (ex-info "Ordered log computation of windows is not supported for session windows." {})))
   (fn [{:keys [range slide] :as m}] 
     (-> m
         (assoc :units (units/standard-units-for (last range)))

  (fn [window]
    (:window/type window)))

(defmethod windowing-builder :fixed
  [window] 
  (fn [{:keys [range] :as m}] 


(defmethod windowing-builder :session
  [window] 
  (when (ordered-log? window)
    (throw (ex-info "Ordered log computation of windows is not supported for session windows." {})))
  (fn [{:keys [timeout-gap] :as m}]
    (-> m
        (assoc :units (units/standard-units-for (last timeout-gap)))
